JOHANNESBURG  A new study of Africa's most endangered carnivores has called for urgent action to save beasts such as the lion, cheetah and Ethiopian wolf from major threats to survival such as hunting and conflict with humans.

Scientists say predators play key ecological roles at the top of the food chain and their presence or absence can say a lot about a habitat's health. But they are in frequent conflict with humans, preying on livestock and sometimes people.

The study, conducted by scientists for the New York based Wildlife Conservation Society (WCS), says Ethiopia's wolf, the African wild dog, the lion and the cheetah are the most endangered predators in Africa.

"Ethiopian wolves ... have vanished from an astonishing 98 percent of their range," the WCS said in a statement. In the past few decades, lions have vanished from 82 percent of the land over which they used to roam, while the elegant cheetah has disappeared from 75 percent of its habitat.

Wild dogs, pack animals detested by livestock farmers, are no longer seen in almost 90 percent of their original territory.

The WCS said all the most vulnerable animals "displayed high degrees of range loss ... and low reproductive rates."

Habitat decline, hunting, road kills and conflict with humans are among the key threats to Africa's carnivores. But not all the continent's meat eaters are in trouble, and some of the smaller and more resilient species seem to be thriving alongside humanity, including the African civet and several species of jackal.

"While these species also prey on livestock and poultry, their adaptability to a variety of habitats makes them less vulnerable to long-term population declines," the WCS said.

The civet and the side-striped jackal appear to have lost none of their former range. Black-backed jackals can be heard baying at the moon in the countryside just outside the continent's financial hub, Johannesburg.

The report recommended focusing conservation action and research on tackling the biggest threats to the animals' survival.

"Africa is world famous for its variety of carnivore species from lions to hyenas," said Dr. Luke Hunter, a co-author of the report who also runs the WCS Global Carnivore Program.

"These animals play a key role in the health of ecosystems, and represent all that is wild about Africa," he said.